Robin Hanson’s excellent essay in Cato Unbound is a proposal to cut medical spending in half. The evidence suggests that this would do little harm and it would help us focus on more helpful activities. I like the way this article summarizes the RAND experiment, searches for the right metaphor, and answers objections.
One question Robin answers is “How could we be this wrong about medicine?” My answer is different than Robin’s. I point to the way many scholarly and scientific disciplines start off useful and become useless. In the case of medicine, the lack of benefit is easier to measure. Try measuring the value of a class in 18th Century English Literature.
That is also a valid reason why we could be so wrong. I can also think of other reasons, such as the analogy to investment advisors who seem to on average provide little value.